The Jauf Formation miospore succession is synthesized in terms of paleoenvironments and sequence stratigraphy. The data set for this study is obtained from four overlapping, continuously cored, and ... [more ▼]

The Jauf Formation miospore succession is synthesized in terms of paleoenvironments and sequence stratigraphy. The data set for this study is obtained from four overlapping, continuously cored, and extensively sampled, boreholes that for a 940 ft composite section. The Jauf Formation ranges in age from late Pragian to latest Emsian. The palynological assemblages, recognized herein, provide the basis for recognizing depositional environments present in the Early Devonian of northern Saudi Arabia. Transgressive – regressive cycles are indicated, not only by lithology but by marked changes in the marine to terrestrially dominated palynological assemblages. Flooding events are recognized by the replacement of spore dominated assemblages by organic-walled microphytoplankton. The maximum flooding interval for the Jauf is reinterpreted based on a correlative event consisting of diverse acritarchs and abundant chitinozoans. [Add details on the paly and sequence stratigraphy here. No.cycles and order.] The new northern Gondwanan biozonation developed by Breuer and Steemans (2012) and used here allows a high-resolution regional biozonation for the Arabian Plate and more intercontinental [?] correlation of the Jauf Formation with other Gondwanan and Euramerican localities. One new spore genus (Zonohilates) and four spore species (Insculptospora maxima, Camarozonotriletes alruwailii, Devonomonoletes crassus and Zonohilates vulneratus) are newly proposed. [less ▲]

Most forensic studies are focused on Diptera pattern colonization while neglecting Coleoptera succession. So far, little information is available on the postmortem colonization by beetles and the ... [more ▼]

Most forensic studies are focused on Diptera pattern colonization while neglecting Coleoptera succession. So far, little information is available on the postmortem colonization by beetles and the decomposition process they initiate under temperate biogeoclimatic countries. These beetles have however been referred to as being part of the entomofaunal colonization of a dead body. Forensic entomologists need increased databases detailing the distribution, ecology and phenology of necrophagous insects, including staphylinids (Coleoptera, Staphylinidae). While pig carcasses are commonly used in forensic entomology studies to surrogate human decomposition and to investigate the entomofaunal succession, very few works have been conducted in Europe on large carcasses. Our work reports the monitoring of the presence of adult rove beetles (Coleoptera, Staphylinidae) on decaying pig carcasses in a forest biotope during four seasons (spring, summer, fall and winter). A total of 23 genera comprising 60 species of rove beetles were collected from pig carcasses. [less ▲]

in Publications of the Astronomical Society of the Pacific [=PASP] (2012), 124

Debris dust in the habitable zones of stars - otherwise known as exozodiacal dust - comes from extrasolar asteroids and comets and is thus an expected part of a planetary system. Background flux from the ... [more ▼]

Debris dust in the habitable zones of stars - otherwise known as exozodiacal dust - comes from extrasolar asteroids and comets and is thus an expected part of a planetary system. Background flux from the Solar System's zodiacal dust and the exozodiacal dust in the target system is likely to be the largest source of astrophysical noise in direct observations of terrestrial planets in the habitable zones of nearby stars. Furthermore, dust structures like clumps, thought to be produced by dynamical interactions with exoplanets, are a possible source of confusion. In this paper, we qualitatively assess the primary impact of exozodical dust on high-contrast direct imaging at optical wavelengths, such as would be performed with a coronagraph. Then we present the sensitivity of previous, current, and near-term facilities to thermal emission from debris dust at all distances from nearby solar-type stars, as well as our current knowledge of dust levels from recent surveys. Finally, we address the other method of detecting debris dust, through high-contrast imaging in scattered light. This method is currently far less sensitive than thermal emission observations, but provides high spatial resolution for studying dust structures. This paper represents the first report of NASA's Exoplanet Exploration Program Analysis Group (ExoPAG). [less ▲]

Aims. We present photometric data of debris disks around HIP 103389 (HD 199260), HIP 107350 (HN Peg, HD206860), and HIP 114948 (HD 219482), obtained in the context of our Herschel Open Time Key Program DUNES (DUst around NEarby Stars). Methods. We used Herschel/PACS to detect the thermal emission of the three debris disks with a 3 sigma sensitivity of a few mJy at 100 um and 160 um. In addition, we obtained Herschel/PACS photometric data at 70 um for HIP 103389. Two different approaches are applied to reduce the Herschel data to investigate the impact of data reduction on the photometry. We fit analytical models to the available spectral energy distribution (SED) data. Results. The SEDs of the three disks potentially exhibit an unusually steep decrease at wavelengths > 70 um. We investigate the significance of the peculiar shape of these SEDs and the impact on models of the disks provided it is real. Our modeling reveals that such a steep decrease of the SEDs in the long wavelength regime is inconsistent with a power-law exponent of the grain size distribution -3.5 expected from a standard equilibrium collisional cascade. In contrast, a very distinct range of grain sizes is implied to dominate the thermal emission of such disks. However, we demonstrate that the understanding of the data of faint sources obtained with Herschel is still incomplete and that the significance of our results depends on the version of the data reduction pipeline used. Conclusions. A new mechanism to produce the dust in the presented debris disks, deviations from the conditions required for a standard equilibrium collisional cascade (grain size exponent of -3.5), and/or significantly different dust properties would be necessary to explain the potentially steep SED shape of the three debris disks presented. (abridged) [less ▲]

We explore the sensitivity and completeness of long baseline interferometric observations for detecting unknown, faint companions around bright unresolved stars. We derive a linear expression for the ... [more ▼]

We explore the sensitivity and completeness of long baseline interferometric observations for detecting unknown, faint companions around bright unresolved stars. We derive a linear expression for the closure phase signature of a faint companion in the high contrast regime (<0.1), and provide a quantitative estimation of the detection efficiency for the currently offered four-telescope configurations at the Very Large Telescope Interferometer. The results are compared to the performances provided by linear and Y-shaped interferometric configurations in order to identify the ideal array. We find that all configurations have a similar efficiency in discovering companions wider than 10mas. Assuming a closure phase accuracy of 0.25deg, that is typical of state-of-the-art instruments, we predict a median dynamic range of up to six magnitudes when stacking observations obtained at five different hour angles. Surveying bright stars to search for faint companions can be considered as an ideal filler programme for modern interferometric facilities because that places few constraints on the choice of the interferometric configuration. [less ▲]

The postal sector has dramatically changed in the recent years with the ongoing liberalization process and the increased competitive pressures from alternative communication channels (e-substitution ... [more ▼]

The postal sector has dramatically changed in the recent years with the ongoing liberalization process and the increased competitive pressures from alternative communication channels (e-substitution). These two effects concur to decrease the mail volume handled by the historical operator which in turn may threaten the financial viability of the universal service and may call for a reform of the universal service. This paper examines the question of reforming the postal universal service, first by considering that the universal service remains confined in the postal word and, latter, by defining a universal service that includes postal and electronic technologies. [less ▲]

In liberalized network industries, entrants can either compete for service using the existing infrastructure (access) or deploy their own infrastructure capacity (bypass). In this paper, we demonstrate ... [more ▼]

In liberalized network industries, entrants can either compete for service using the existing infrastructure (access) or deploy their own infrastructure capacity (bypass). In this paper, we demonstrate that, under the threat of bypass, the access price set by an unregulated and vertically integrated incumbent is compatible with productive efficiency. This means that the entrant bypasses the existing infrastructure only if it can produces the network input more efficiently. The incumbent lowers the access price compared to the ex-post efficient level to strategically deter inefficient bypass by the entrant. Accordingly, from a productive efficiency point of view, there is no need to regulate access prices when the entrant has the option to bypass. Despite that, we show that restricting the possibilities of access might be profitable for consumers. [less ▲]